This is a given. If you don't have an understanding of style, in general, how can you write about it? It makes you more believable. If you've established a strong sense of personal style, you will better be able to articulate ideas abotu style to your readers. When someone reads something you've written and sees what you look like/how you dress, they identify how you look with your writing. If you look like a pud, they may not take your writing seriously. Shallow, but true.
Dress the Part